Pyrazole Compounds : Synthesis, molecular structure, chemical reactivity, experimental and theoretical DFT FTIR spectra

Abstract

Abstract Eight Pyrazole ligands which are prepared by condensation of different amines with Pyrazole and 3,5-dimethylpyrazole, then characterized using FTIR. This analysis was recorded using KBr pellets on FTIR-8400S spectrometer, and then the spectra are compared with the ones calculated by the Density Functional Theory (DFT) calculations with GAUSSIAN 09W suite. Experimental and calculated vibrational spectra demonstrate a good correlation with some difference in %T and frequency (cm-1) shown in the theoretical spectra due to the presence of all predicted vibrational modes. The optimized structure, HOMO, LUMO orbitals and some other quantum descriptors were also determined to reveal their chemical reactivity properties. The similarities and the differences between the theoretical and the experimental vibrational analysis of all the prepared ligands have been highlighted. The calculated FTIR spectra by DFT shows perfect agreement with the experimental ones and generated positive value of vibrations indicate calculations are at the global minima.